1. Field of the Invention
The present invention provides methods of modulating in optical communication, said methods comprising means for accelerating charged particles so as to establish positive net emission of electromagnetic radiation, said method comprising means for driving accelerated particles, as well as comprising means for transforming an optical beam into a delayed electromagnetic wave, and also converting the kinetic energy of charged particles into energy of the same electromagnetic wave. The steps of transforming as well as converting take place simultaneously in the same interaction region, which is formed by a wave-guide structure. The step of transforming may be implemented e.g., as said wave guide structure having suitable geometric configuration and dielectric/metal properties. Said manipulating means may be implemented, e.g., as deflector, which is driven by a small voltage, alternatively, other systems for changing of charged particle beam properties can be exploited for said manipulating.
Prior art optical techniques for modulating signals may take the form of a mechanical shutter, which is interposed between areas of light transmission or directly on surface of light-guide fiber. These shutters tend to have natural limit for velocity determined by mechanical part motion. The best “push-pull” configuration modulator, which has magnitude ˜1.5 microns, operates with voltage ˜2 volts and at a frequency of ˜40 GHz. Another technique includes the use of a semiconductor optical guide, across which electrical voltage or magnetic field may be applied. This voltage (or field) alters the optical characteristics of such guide to change or modulate the light passing therethrough. This provides a workable optical device and its speed of modulation is limited by inertia of electrical properties of solid state. The best example of characteristics-changing semiconductor devices can be efficient in transmitting data at rates of speed ˜160 Gbits per each carrying frequency channel before wavelength division multiplexing. Other types of solid-state devices use acousto-optical waves or surface plasmon and don't have better rates of speed than previous example. Apparently, modulation by direct superposition of modulating light and propagating light will have higher rates of speed, then in case of using of solid-state electro-inertial devices. Initially it had been proposed that the modulating mode should be added to other modes into multimode light-guide fiber. But in that type of modulation the use of multimode fiber was obligatory and there were nothing said about the technique of producing high-speed changed modulating light. Later it has been suggested, that low-power diode laser, which modulated an output power of fiber laser, could be used. However, the necessary semiconductor diode has the same modulating speed limitation as other solid-state devices. At the present, therefore, new knowledge shows that sophisticated multimode regime is not obligatory and, exactly, driven radiation of free moving charged particles should be used to produce modulating light for the fastest modulation process in optical data transmitting.
2. Background of the Related Art